Calcium oxide (CaO) or hydrated lime is a kind of chemical compound having a wide field of use. It is a white, caustic and alkaline solid. In industry, it is obtained with removing carbon dioxide by melting the limestone at high temperatures. It is oxidized when reacted with water and thus calcium hydroxide is formed. It is a compound having ionic bond.
Calcium oxide is widely used in industry, e.g., binders in construction mortars and plasters, purifying in iron and steel industry, pH modifier for rehabilitation of acidic soils, intermediate product or final product component in preparation of various chemical materials, additive in road surface construction and in many other areas.
Metal oxides are especially known with their antibacterial properties. These properties point out to new usage areas of metal oxides. It seems possible in these areas may be related to medical applications such as food.
The food that offered to the consumer at present contain lots of chemicals except the main components. These chemical substances are classified as carbohydrates, lipids, proteins, vitamins and minerals. Food security can be defined as adequate for balanced nutrition, sustainable, economically accessible and healthy food supply to people. Increasing food production, preventing the loss of produced food, storage while maintaining the quality of the food and extension of shelf life are gaining importance for ensuring food security. In this case, production and consumption relations of foods make a technological necessity the using of additives. Nevertheless, recent researches show that additives can create risks for consumers. Using of these substances was restricted as a result of many research.
Food additives can be synthetic or natural origin. In particular, doubts about harmful effects of synthetic food additives to human health is extremely strong. Especially, the preservative used to prolong the shelf life of any food is considered to pose a risk to human health. However, it is clear that the need for food with a long shelf life when considering the present level of population growth and food supply. Most commonly used additives in prolonging the shelf life of food are sodium benzoate, potassium sorbate and sodium metabisulphite. But, it carries all doubts on the reliability of these products for human health. Therefore, it is of vital importance using additive for food which was known as obtained from natural sources and not harmful to human body. In addition, purity levels of natural origin substances of this type is very important. Briefly, requirements of food industry toward additives which have high purity and also known as reliable in terms of health is too much. In food codex, E-529 known as calcium oxide (CaO) is used as acidity regulator and anti-caking. There is also no known side effects. However, purity of the calcium oxide for food applications is not at the desired level, and the existing ones enforce the usage limits in terms of economical.
In addition, the high confidence interval of calcium oxide may lead to new approaches to disease treatment area. But, there is no adequate research and application in medical practice.
Owing to these disadvantages, it is clear that there is need for new approaches for in technical fields related to calcium oxide, reliability, ease of access, food and medical applications and innovation is required.